161438687451 has 6 divisors (see below), whose sum is σ = 233189215220. Its totient is φ = 107625791628.

The previous prime is 161438687447. The next prime is 161438687471. The reversal of 161438687451 is 154786834161.

161438687451 is a `hidden beast` number, since 161 + 438 + 6 + 8 + 7 + 45 + 1 = 666.

It is not a de Polignac number, because 161438687451 - 2² = 161438687447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161438687471) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8968815961 + ... + 8968815978.

Almost surely, 2^161438687451 is an apocalyptic number.

161438687451 is a deficient number, since it is larger than the sum of its proper divisors (71750527769).

161438687451 is a wasteful number, since it uses less digits than its factorization.

161438687451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17937631945 (or 17937631942 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The spelling of 161438687451 in words is "one hundred sixty-one billion, four hundred thirty-eight million, six hundred eighty-seven thousand, four hundred fifty-one".